JP2002116563A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high sensitivity to near infrared light, excellent in electrical characteristics, less liable to the lowering of its sensitivity due to repetitive use, having stable potential by electrification and excellent also in wear resistance. SOLUTION: A photosensitive layer 4 formed on the electrically conductive substrate 1 of the electrophotographic photoreceptor contains a specified crystal form oxo-titanyl phthalocyanine as an electric charge generating material 2, a diamine compound having a benzofuran, benzothiophene or indole ring as an electric charge transferring material 3, certain amounts of a specified polycarbonate resin and a specified polyester resin as binder resins, α-tocopherol or 2,6-di-t-butyl-4-methyl-phenol as an antioxidant and dimethylpolysiloxane as a leveling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor using a specific crystalline oxotitanyl phthalocyanine compound as a charge generating substance and using a benzofuran, benzothiophene or diamine compound having an indole ring as a charge transfer substance. In particular, the present invention relates to an electrophotographic photoreceptor having high sensitivity in a near-infrared wavelength region.

[0002]

2. Description of the Related Art At present, electrophotographic photoconductors (hereinafter, also simply referred to as "photoconductors") put into practical use include an inorganic photoconductor using an inorganic material and an organic photoconductor using an organic material. are categorized.

Conventionally, inorganic materials have been mainly used for electrophotographic photoreceptors from the viewpoint of both sensitivity and durability. Representative inorganic photoconductors include amorphous selenium (a-Se) and amorphous selenium arsenic (a-A).
selenium-based photoconductor composed of sSe) or the like; a photoconductor in which dye-sensitized zinc oxide (ZnO) or cadmium sulfide (CdS) is dispersed in a binder resin; a photoconductor using amorphous silicon (a-Si); There is.

The selenium-based photoconductor and the photoconductor using CdS have problems in heat resistance and storage stability.
Being toxic, its disposal causes pollution. Further, the ZnO resin dispersed photoreceptor is hardly used at present because it has low sensitivity and low durability. The a-Si photoreceptor is attracting attention as a non-polluting inorganic photoreceptor and has advantages such as high sensitivity and high durability. However, the a-Si photoreceptor uses plasma CVD (Ch
It has drawbacks such as image defects caused by a manufacturing process using an emical vapor deposition method, and a drawback that costs are increased due to low productivity. As described above, the inorganic materials have various disadvantages.

[0005] Since there are many kinds of organic materials themselves, by appropriately selecting them, it is possible to produce a non-toxic material having good storage stability. In addition, since an organic material can easily form a thin film by coating, there is an advantage that a photoreceptor can be manufactured at low cost. Further, in recent years, the sensitivity and durability of organic photoreceptors have been rapidly improved.

[0006] From the above, at present, organic materials have been used for electrophotographic photoreceptors except in special cases.

In recent years, laser beam printers which use laser light as a light source instead of the conventional white light and have advantages of high speed, high image quality and low impact have become widespread. Development is desired. In particular, various methods using a semiconductor laser as a light source, which has been remarkably progressing in recent years, have been tried.
Since it is around 00 nm, there is a strong demand for a photoreceptor having high sensitivity to long wavelength light around 800 nm.

[0008] As organic materials meeting the demand, methine squarate dyes, indoline dyes, cyanine dyes, pyrylium dyes, polyazo dyes, phthalocyanine dyes, naphthoquinone dyes and the like have been known. Methine squarate dyes, indoline dyes, cyanine dyes and pyrylium dyes can be made longer in wavelength, but lack the repetitive properties as practical stability. At present, it is difficult for polyazo dyes to have a longer wavelength, which is disadvantageous in production, and naphthoquinone dyes have difficulty in sensitivity.

A photoreceptor using a metal phthalocyanine compound among phthalocyanine dyes is disclosed in US Pat.
No. 989, JP-A-49-11136, U.S. Pat. No. 4,214,907 and British Patent No. 126.
As is apparent from the specification of No. 8422 and the like, the sensitivity peak varies depending on the central metal.
The wavelength is relatively long at 750 nm.

Japanese Unexamined Patent Publication (Kokai) No. 59-49544 discloses that an oxotitanyl phthalocyanine is vapor-deposited on a substrate to form a charge-generating layer, on which 2,6-dimethoxy-phthalocyanine is formed.
An electrophotographic photosensitive member provided with a charge transfer layer mainly containing 9,10-dihydroxyanthracene is described. The photoreceptor has a high residual potential and is somewhat restricted in usage.
The reproducibility of various electrical characteristics is disadvantageous due to the non-uniformity of the film thickness due to the vapor deposition method, and there is no choice but to be restricted in mass production of the photoconductor on an industrial scale.

In recent years, among these phthalocyanines, oxotitanyl phthalocyanines exhibiting high sensitivity have been energetically studied. Even oxotitanyl phthalocyanine alone is classified into many crystal forms based on the difference in the diffraction angle of the X-ray diffraction spectrum, as described in the Journal of the Institute of Electrophotography, Vol. 32, No. 3, page 282. Specifically, the characteristic crystal forms are shown as follows: α-type in JP-A-61-217050 and JP-A-61-239248, A-type in JP-A-62-67094, 1963-366
And JP-A-63-198067,
Mold, JP-A-63-20365, JP-A-2-825
No. 6 and JP-A-1-17066, Y-type,
JP-A-3-54265 discloses an M-type,
No. 264 describes an M-α type crystal, and Japanese Unexamined Patent Publication No. 3-128973 describes an I type crystal. JP-A-62-67
No. 094 describes type I and II crystals.

The crystal of oxotitanyl phthalocyanine whose lattice constant is known from structural analysis is C
Type, Phase I type and Phase II type. P
Phase II belongs to the triclinic system, and Phase I and C belong to the monoclinic system. From these known crystal lattice constants, when analyzing the crystal forms described in the above publication, A-type and I-type belong to Phase I-type, and α-type and B-type belong to P-type.
It belongs to the case II type, and the M type belongs to the C type. A similar analysis is described in the literature (J. of Imaging Science and Technology Vo
l.36, No. 6, 1993, p605-609).

As a problem of the photoreceptor itself, the occurrence of interference fringes, which is considered to be mainly caused by the reflection of the laser beam used for exposure on the substrate, occurs, and several techniques are known as methods for solving the problem. One known method is to increase the thickness of the charge generation layer and absorb the exposed laser beam to eliminate reflection from the substrate. However, there is a limit to the thickness that can be formed by a conventional vapor deposition method. And its control is also difficult. On the other hand, the method of forming a charge generation layer by applying a binder resin dispersion liquid has an arbitrary thickness, has good reproducibility, is easy to control, does not require a high vacuum device at the time of vapor deposition, and requires heating. Thermal decomposition and denaturation can be avoided. In addition, the binder resin dispersion liquid coating method is advantageous because there is no need to crystallize a vapor-deposited product by various methods after vapor deposition, as in the vapor deposition method, which is troublesome in industrial production.

JP-A-61-109056 discloses an electrophotographic photosensitive member in which a charge transfer layer containing a hydrazone compound and a binder resin is laminated on a charge generation layer containing an oxotitanyl phthalocyanine compound and a binder resin. To provide a photoreceptor having a sensitivity around 800 nm. The photoreceptor does not reach the sensitivity required for high image quality and high speed at present.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic device which is highly sensitive to near-infrared light and has excellent electrical characteristics, is unlikely to cause a decrease in sensitivity due to repeated use, has a stable charging potential and is excellent in wear resistance. An object of the present invention is to provide a photoreceptor.

[0016]

According to the present invention, a photosensitive layer formed on a conductive substrate is used as a charge generation substance in a Bragg angle (2θ ± 0.2 °) in an X-ray diffraction spectrum.
7.3 °, 9.4 °, 9.6 °, 11.6 °, 13.3
°, 17.9 °, 24.1 ° and 27.2 ° show major diffraction peaks, of which the overlapping peak bundle of 9.4 ° and 9.6 ° shows the largest diffraction peak, and 27. 2
Contains a crystalline oxotitanyl phthalocyanine having a peak at a second largest peak, and contains, as a charge transfer material, a benzofuran, benzothiophene or a diamine compound having an indole ring represented by the following general formula (I): An electrophotographic photoreceptor characterized by the following:

[0017]

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(Wherein, Ar ¹ represents an arylene group which may have a substituent, a divalent heterocyclic group which may have a substituent or an alkylene group having 1 to 5 carbon atoms which may have a substituent. Ar ² is an aryl group which may have a substituent, a heterocyclic group which may have a substituent, an aralkyl group which may have a substituent, an alkyl group having 1 to 5 carbon atoms which may have a substituent, A fluoroalkyl group having 1 to 5 carbon atoms which may be contained or a perfluoroalkyl group having 1 to 5 carbon atoms which may contain a substituent, wherein R ¹ is an alkyl group having 1 to 3 carbon atoms which may contain a substituent; A fluoroalkyl group having 1 to 5 carbon atoms which may have a substituent, a perfluoroalkyl group having 1 to 5 carbon atoms which may have a substituent, an alkoxy group having 1 to 3 carbon atoms, and a dialkyl having 1 to 3 carbon atoms Amino group or hydrogen source A represents an alkyl group having 1 to 3 carbon atoms that may have a substituent, a fluoroalkyl group having 1 to 5 carbon atoms that may have a substituent, and a par having 1 to 5 carbon atoms that may have a substituent. Fluoroalkyl group, carbon number 1
Represents an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and n represents 1 to 4
Indicates an integer. However, when n is 2 or more, each of a may be the same or different, and may form a ring with each other. X represents an oxygen atom, a sulfur atom or N-R ^2, R ²
Represents an alkyl group having 1 to 3 carbon atoms which may have a substituent, a fluoroalkyl group having 1 to 5 carbon atoms which may have a substituent or a perfluoroalkyl group having 1 to 5 carbon atoms which may have a substituent. . )

According to the present invention, oxotitanyl phthalocyanine of a specific crystal type having a high sensitivity at around 800 nm, a stable crystal type and excellent crystal stability against solvents and heat, and a benzofuran, benzothiophene or indole ring Provided is an electrophotographic photoreceptor having good chargeability, extremely low residual potential, good durability, and strong sensitivity at about 800 nm by using in combination with an amine compound having excellent chargeability. Can be.

Further, the invention is characterized in that the photosensitive layer has a laminated structure including a charge generation layer containing the charge generation material and a charge transfer layer containing the charge transfer material.

According to the present invention, since the oxotitanyl phthalocyanine is contained in the charge generation layer and the amine compound is contained in the charge transfer layer, the chargeability is excellent, the residual potential is extremely low, and the durability is good. With 8
It is possible to provide a laminated electrophotographic photoreceptor having a strong sensitivity of about 00 nm.

Further, the present invention is characterized in that the photosensitive layer comprises a single layer containing the charge generation material and the charge transfer material.

According to the present invention, by dispersing the oxotitanyl phthalocyanine and the amine compound in a binder resin, the chargeability is excellent, the residual potential is extremely low, the durability is good, and the viscosity is about 800 nm. A single-layer type electrophotographic photosensitive member having high sensitivity can be provided.

Further, the present invention is characterized in that an intermediate layer is provided between the conductive support and the photosensitive layer.

According to the present invention, by providing the intermediate layer, the adhesiveness between the conductive support and the photosensitive layer can be enhanced, so that an electrophotographic photosensitive member having stable sensitivity can be provided.

Further, in the present invention, the charge transfer layer may comprise, as a binder resin, a polymer of a vinyl compound or a copolymer thereof, a polyester resin, a polycarbonate resin, a polyarylate resin, a polysulfone resin, a polyvinyl butyral resin, a phenoxy resin, a cellulose resin. It contains at least one member selected from the group consisting of a base resin, a urethane resin, and an epoxy resin.

According to the present invention, by using a specific resin as a binder resin for the charge transport layer, it is possible to provide a function-separated type electrophotographic photosensitive member having excellent abrasion resistance.

Further, in the present invention, the photosensitive layer may comprise, as a binder resin, a polymer of a vinyl compound and a copolymer thereof;
It is characterized by containing at least one selected from the group consisting of a polyester resin, a polycarbonate resin, a polyarylate resin, a polysulfone resin, a polyvinyl butyral resin, a phenoxy resin, a cellulosic resin, a urethane resin, and an epoxy resin.

According to the present invention, a single-layer type electrophotographic photosensitive member having excellent abrasion resistance can be provided by using a specific resin as a binder resin for the photosensitive layer.

Further, the present invention is characterized in that the binder resin contains a polycarbonate resin represented by the following general formula (II).

[0031]

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Wherein b and c are an alkyl group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, Represents an aralkyl group having 7 to 17 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom or a hydrogen atom, and X ² represents a single bond or a substituted An alkylene group having 1 to 10 carbon atoms which may have a group, a cyclic alkylidene group having 1 to 10 carbon atoms which may have a substituent, and an arylene group having 6 to 12 carbon atoms which may have a substituent , A sulfonyl group or a carbonyl group, m and l are
U represents an integer of 1 to 4, and u represents an integer of 10 to 200. Z
Is an alkylene group having 1 to 5 carbon atoms which may have a substituent, an arylene group having 6 to 12 carbon atoms, or a C 7 to 1
7 represents an arylenealkyl group. W represents an alkyl group having 1 to 5 carbon atoms which may have a substituent, an alkenyl group having 2 to 5 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms, or a substituent. Represents an alkyl ester group having 1 to 5 carbon atoms, an aryl ester group having 6 to 12 carbon atoms which may have a substituent, a carboxyl group, an aldehyde group, a hydroxyl group, a halogen atom, or a hydrogen atom. )

According to the present invention, an electrophotographic photosensitive member having excellent abrasion resistance can be provided by using a specific polycarbonate resin as a binder resin for the photosensitive layer.

Further, the present invention is characterized in that the binder resin contains a polyester resin represented by the following general formula (III) in an amount of from 5% by weight to 50% by weight based on the total amount of the binder resin.

[0035]

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(In the formula, g, h, and i represent an integer of 1 to 10, and v, w, x, and y represent an integer of 10 to 1,000.)

According to the present invention, when a certain amount of a specific polyester resin is used together with a specific polycarbonate resin as a binder resin for the photosensitive layer, the mixing effect tends to be weak at less than 5% by weight, An electrophotographic photoreceptor excellent in abrasion resistance can be provided without causing a problem such as a decrease in viscosity as a coating liquid when the content exceeds 50% by weight.

Further, the present invention is characterized in that the weight ratio of the polycarbonate resin / the polyester resin is in the range of 9/1 to 7/3.

According to the present invention, by containing a polycarbonate resin and a polyester resin in a constant weight ratio, it is possible to provide an electrophotographic photosensitive member having more excellent abrasion resistance.

The present invention is also characterized in that the photosensitive layer contains α-tocopherol as an antioxidant and the weight ratio of antioxidant / charge transfer material is 0.1 / 100 or more and 5/100 or less. I do.

According to the present invention, by adding a certain amount of α-tocopherol as an antioxidant to the charge transfer material, the stability of the coating solution for the charge transfer layer can be improved, and the potential characteristics can be improved. An electrophotographic photoreceptor excellent in the above can be provided.

Further, according to the present invention, the photosensitive layer contains 2,6-di-t-butyl-4-methyl-phenol as an antioxidant, and the weight ratio of the antioxidant / charge transfer material is 0.1%.
It is not less than 1/100 and not more than 50/100.

According to the present invention, the coating liquid for the charge transfer layer is prepared by containing a certain amount of 2,6-di-t-butyl-4-methyl-phenol as an antioxidant with respect to the charge transfer material. Can increase the stability of
An electrophotographic photosensitive member having excellent potential characteristics can be provided.

Further, the present invention is characterized in that the surface layer contains dimethylpolysiloxane in a weight ratio of dimethylpolysiloxane / binder resin of 0.001 / 100 or more and 5/100 or less.

According to the present invention, by including dimethylpolysiloxane as a leveling agent at a constant weight ratio to the binder resin, a photosensitive member having excellent surface properties can be obtained, and the potential characteristics can be improved. be able to.

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION An electrophotographic photoreceptor according to an embodiment of the present invention comprises, on a conductive support, a specific oxotitanyl phthalocyanine compound as a charge generating substance and a specific diamine compound as a charge transfer substance. And a photosensitive layer containing a specific binder resin.

The specific oxotitanyl phthalocyanine compound used as the charge generating substance has a Bragg angle (2θ ± 0.2 °) of 7.3 ° and 9.3 in the X-ray diffraction spectrum.
4 °, 9.6 °, 11.6 °, 13.3 °, 17.9
°, 24.1 ° and 27.2 ° show major diffraction peaks, of which the overlapping peak bundle of 9.4 ° and 9.6 ° shows the maximum diffraction peak, and the peak at 27.2 ° shows It is a crystalline oxotitanyl phthalocyanine characterized by showing the second largest peak.

The method for synthesizing oxotitanyl phthalocyanine is described in Moser and Thomas, "Phthalocianine Compound" (MOSER and THOMAS. "Phthalocianine Compound").
s ''), for example, by a method in which o-phthalonitrile and titanium tetrachloride are heated and melted or heated in the presence of an organic solvent such as α-chloronaphthalene. And dichlorotitanium phthalocyanine can be obtained in good yield.
By hydrolyzing the obtained dichlorotitanium phthalocyanine with a base or water, oxotitanyl phthalocyanine is obtained. Also, oxotitanyl phthalocyanine can be obtained by heating 1,3-diiminoisoindoline and tetrabutoxytitanium in an organic solvent such as N-methylpyrrolidone. The obtained oxotitanyl phthalocyanine may contain a phthalocyanine derivative in which a hydrogen atom of a benzene ring is substituted with a substituent such as chlorine, fluorine, nitro, cyano or sulfone.

By treating such an oxotitanyl phthalocyanine composition with a water-immiscible organic solvent such as dichloroethane in the presence of water, a specific crystal form in the present invention is obtained. As a method of treating oxotitanyl phthalocyanine with a water-immiscible organic solvent in the presence of water, a method of swelling oxotitanyl phthalocyanine with water and treating it with an organic solvent, and without performing swelling treatment, Examples thereof include, but are not limited to, a method in which the compound is added to a solvent and oxotitanyl phthalocyanine powder is charged therein.

As a method of swelling oxotitanyl phthalocyanine with water, for example, a method of dissolving oxotitanyl phthalocyanine in sulfuric acid and precipitating in water to form a wet paste can be mentioned. In addition, a method of swelling oxotitanyl phthalocyanine with water using a stirring / dispersion device such as a homomixer, a paint mixer, a ball mill, and a sand mill to form a wet paste is also included, but the method is not limited to these methods. Further, the oxotitanyl phthalocyanine composition obtained by hydrolysis is subjected to a stirring treatment or a milling treatment with a mechanical strain for a sufficient time in a solution or a solution in which a binder resin is dissolved, whereby the oxo titanyl phthalocyanine composition is specified in the present invention. Is obtained.

As an apparatus used for this treatment, a homomixer, a paint mixer, a disperser, an agitator, a ball mill, a sand mill, a paint shaker, a dyno mill, an attritor, an ultrasonic disperser, and the like can be used in addition to a general stirring apparatus. it can. After the treatment, the mixture may be filtered, washed with methanol, ethanol, water, or the like, and isolated. Alternatively, after the treatment, a binder resin may be added and used as it is as a coating solution. Further, a resin to which a binder resin has been added in advance during the treatment can be used as it is as a coating solution.

Among the known oxotitanyl phthalocyanines of the crystal type, there are Y type and M-α type with relatively good photosensitivity characteristics. There are other types I and M, which are crystals obtained by treating the M-α type as described in the Journal of the Institute of Electrophotography, Vol. 32, No. 3, page 282. And properties are similar, so they are included in M-α type. The above-mentioned new crystal form in the embodiment of the present invention is:
Not only does it match neither the Y-type nor the M-α-type, but it shows better properties.

Regarding the crystal type in the present embodiment, the M-α type has a Bragg angle (2θ ± 0.2) for the main peak position.
°) 7.2 °, 14.2 °, 24.0 ° and 27.1.
7.3 °, 9.4 °, 9.6 °,
It is 11.6 °, 13.3 °, 17.9 °, 24.1 ° and 27.2 °, which is clearly a crystal system completely different from the M-α form. As for the Y type, the main peak positions are 9.6 °, 11.7 °, 15.0 °, 24.1 ° and 27.1 °, which are similar to the peak positions of the crystal type in the present invention. , The two spectra differ greatly in the relationship of their relative intensities. That is, the maximum peak position is the Bragg angle (2θ ± 0.2 °), and the crystal form in the present embodiment is a peak bundle where 9.4 ° and 9.6 ° overlap, whereas the Y form is Is 27.3 °. By the way, M-α type is 27.3 °. Since the relative intensity is determined by the crystal type, the remarkable difference between the peak intensities of the two spectra is due to the fact that both crystal systems are different.

For the Y-type spectrum, see JP-A-7-2
As disclosed in JP-A-71073, a Bragg angle of 1
Two distinct peaks are observed around 8 ° and around 24 °, respectively, whereas the crystal forms in the present embodiment have Bragg angles (2θ ± 0.2 °) of 17.9 ° and 24.
At 1 °, there is a great difference in that only one peak is seen. Furthermore, the crystal-type oxotitanyl phthalocyanine of the present embodiment is superior to the photosensitivity characteristic, the repetitive use characteristic and the solvent stability.

Japanese Unexamined Patent Publication No. Hei 8-209023 discloses an oxotitanyl phthalocyanine having a maximum peak at a Bragg angle (2θ ± 0.2 °) of 9.6 °. This is a new crystal type that has not been reported in the Journal of the Electrographic Society of Japan, Vol. 32, No. 3, page 282. The crystal form could not be produced by any synthesis method by the inventors of the present invention, and the crystal form in the embodiment of the present invention could not be compared with characteristics such as photosensitivity characteristics. . However, in the above crystal type, the main peak is a Bragg angle (2θ ± 0.2 °) 7.2.
2 °, 9.60 °, 11.60 °, 13.40 °, 1
4.88 °, 18.34 °, 23.62 °, 24.14
° and 27.32 °,
In the crystal form according to the present embodiment, 18.34 ° ± 0.3.
There are no peaks at 2 ° and 23.62 ° ± 0.2 °. Therefore, the new crystal form in the embodiment of the present invention is different from the above crystal form.

The specific phthalocyanine composition according to the embodiment of the present invention is not limited to the one produced by the above-mentioned production method, but shows a specific peak regardless of the production method. As long as it is included. The oxotitanyl phthalocyanine thus obtained exhibits excellent properties as a charge generating substance of an electrophotographic photoreceptor. In the embodiment of the present invention,
A charge generating substance other than the oxotitanyl phthalocyanine may be used in combination. As the charge generating material used in combination, α-type, β-type, Y-type and amorphous oxotitanyl phthalocyanine which are different in crystal form from the specific oxotitanyl phthalocyanine in the present invention, other phthalocyanines, and azo pigments, anthraquinone pigments, perylene pigments And polycyclic quinone pigments and squarium pigments.

The specific diamine compound used as the charge transfer material has a benzofuran, benzothiophene or indole ring, and is preferably a diamine compound represented by the following formula (I).

[0058]

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In the general formula (I), Ar ¹ represents an arylene group which may have a substituent, a divalent heterocyclic group which may have a substituent or an alkylene group having 1 to 5 carbon atoms which may have a substituent. Is shown.

Specific examples of Ar ¹ include phenylene, naphthylene, pyridylene, biphenylene and butylene.

In the general formula (I), Ar ² represents an aryl group which may have a substituent, a heterocyclic group which may have a substituent,
An aralkyl group which may have a substituent, an alkyl group having 1 to 5 carbon atoms which may have a substituent, a fluoroalkyl group having 1 to 5 carbon atoms which may have a substituent or 1 to 5 carbon atoms which may have a substituent; 5 represents a perfluoroalkyl group.

Specific examples of Ar ² include aryl groups such as phenyl, tolyl, anisyl, naphthyl, pyrenyl and biphenyl, benzofuryl, benzothiophenyl,
Heterocyclic groups such as N-methylindolyl, benzothiazolyl, benzoxazolyl and N-ethylcarbazolyl, and alkyl groups such as n-propyl and isopropyl.

In the general formula (I), R ¹ represents an alkyl group having 1 to 3 carbon atoms which may have a substituent, a fluoroalkyl group having 1 to 5 carbon atoms which may have a substituent or a substituent. A perfluoroalkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, or a hydrogen atom.

Specific examples of R ¹ include a hydrogen atom, an alkyl group such as methyl, ethyl, n-propyl and isopropyl, an alkoxy group such as methoxy and ethoxy, and a dialkylamino group such as dimethylamino and diethylamino. .

In the general formula (I), a may contain a C1 to C3 alkyl group which may contain a substituent, a C1 to C5 fluoroalkyl group which may contain a substituent, or a substituent. C1-5 perfluoroalkyl group, C1
Represents an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and n represents 1 to 4
Indicates an integer. However, when n is 2 or more, each of a may be the same or different, and may form a ring with each other.

Specific examples of a include a hydrogen atom and an alkyl group such as methyl, ethyl, n-propyl and isopropyl; an alkoxy group such as methoxy, ethoxy, n-propoxy and isopropoxy; dimethylamino;
And dialkylamino groups such as diethylamino and diisopropylamino, and halogen atoms such as fluorine, chlorine and bromine. Generally, an electron donating substituent is preferred.

In the general formula (I), X represents an oxygen atom, a sulfur atom or N—R ² , and R ² represents an alkyl group having 1 to 3 carbon atoms which may have a substituent or a substituent. A good fluoroalkyl group having 1 to 5 carbon atoms or a perfluoroalkyl group having 1 to 5 carbon atoms which may contain a substituent is shown.

Specific examples of X include an oxygen atom, a sulfur atom, N-methyl and N-ethyl.

In particular, among the diamine compounds represented by the general formula (I), as the compounds excellent from the viewpoints of electrophotographic properties, cost and production, Ar ¹ is a phenylene group, biphenylene group or naphthylene group, and Ar ² is A phenyl group, a p-tolyl group, a benzofuryl group, a benzothiophenyl group or an N-methylindolyl group, those in which R ¹ and a are a hydrogen atom, and X is an oxygen atom or a sulfur atom.

Next, specific examples of the diamine compound represented by the general formula (I) are shown in the following Tables 1 to 3, but the diamine compound of the present invention is not limited thereto.

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

By containing the diamine compound represented by the general formula (I) as a charge transfer material, an electrophotographic photosensitive member having excellent charging characteristics can be provided.

Examples of the specific binder resin include vinyl polymers such as polymethyl methacrylate, polystyrene and polyvinyl chloride, copolymers thereof, polycarbonate resin, polyester resin, polyester carbonate resin, polysulfone resin, phenoxy resin, epoxy resin And silicone resin. These may be used alone or as a mixture of two or more kinds, and a partially crosslinked thermosetting resin may also be used. In particular, a polycarbonate resin represented by the following general formula (II) and a mixed resin of a polycarbonate resin represented by the following general formula (II) and a polyester resin represented by the following general formula (III) are suitable as the binder resin. This further enhances the abrasion resistance of the photoconductor.

[0076]

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In the general formula (II), b and c are each
An alkyl group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, and an aralkyl group having 7 to 17 carbon atoms which may have a substituent An alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms,
Represents a halogen atom or a hydrogen atom. X ² may be a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, a cyclic alkylidene group having 1 to 10 carbon atoms which may have a substituent, or a substituent. Represents an arylene group, a sulfonyl group, or a carbonyl group having 6 to 12 carbon atoms;
And 1 are integers of 1 to 4, and u is an integer of 10 to 200.

In the general formula (II), Z represents an optionally substituted alkylene group having 1 to 5 carbon atoms, an arylene group having 6 to 12 carbon atoms, or an arylene alkyl group having 7 to 17 carbon atoms. Represents W represents an alkyl group having 1 to 5 carbon atoms which may have a substituent, an alkenyl group having 2 to 5 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms, or a substituent. An alkyl ester group having 1 to 5 carbon atoms, an aryl ester group having 6 to 12 carbon atoms which may have a substituent, a carboxyl group, an aldehyde group, a hydroxyl group, a halogen atom,
Or represents a hydrogen atom.

Next, specific examples of the polycarbonate resin represented by the general formula (II) include those having the structures shown in Table 4 below, but are not limited thereto.

[0080]

[Table 4]

[0081]

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In the general formula (III), g, h and i are
Represents an integer of 1 to 10, and v, w, x and y are 10 to
Represents an integer of 1000.

The polyester resin of the general formula (III) is
5% by weight or more based on the entire binder resin
0% by weight or less, more preferably 10% by weight or more and 30% by weight or less. If the amount is less than 5% by weight, the effect of mixing tends to be weak. If the amount exceeds 50% by weight, problems such as a decrease in viscosity of the coating liquid may be caused.

The diamine compound represented by the general formula (I) is preferably used in an amount of 0.1 to 1 part by weight of the binder resin.
2 parts by weight or more and 1.5 parts by weight or less, more preferably 0.3 part by weight
It is used in an amount of at least 1.2 parts by weight.

FIG. 1 is a sectional view schematically showing an example of an electrophotographic photosensitive member having a laminated photosensitive layer. FIG. 2 is a cross-sectional view schematically illustrating an example of an electrophotographic photosensitive member having a dispersion type photosensitive layer. FIG. 3 is a cross-sectional view showing an example having an intermediate layer 7 in the electrophotographic photoreceptor of FIG. FIG.
FIG. 3 is a cross-sectional view illustrating an example having an intermediate layer 7 in the electrophotographic photosensitive member of FIG. The electrophotographic photosensitive member of FIG.
The laminated photoreceptor has a laminated photoconductive layer 4 composed of two layers, a charge generating layer 5 containing the charge generating substance 2 and a charge transporting layer 6 containing the charge transporting substance 3 thereon. The electrophotographic photoreceptor shown in FIG. 2 is a dispersion-type photoconductor comprising a charge generation material 2 and a charge transfer material 3 by dispersing a charge generation material 2 in a charge transfer layer on a conductive support 1. Photosensitive layer 1
4 is a single-layer type photoreceptor. 3 and 4, the intermediate layer 7 is composed of the conductive support 1 and the photosensitive layer 4 or 14.
Is provided as a commonly used known intermediate layer. By providing the intermediate layer 7, the adhesiveness between the conductive support and the photosensitive layer can be increased, so that an electrophotographic photosensitive member with stable sensitivity can be provided.

The structure of the electrophotographic photosensitive member according to the embodiment of the present invention includes a laminated type as shown in FIG. 1, a single-layer type as shown in FIG. 2, or an intermediate layer 7 as shown in FIGS. It can be a laminated type or a single layer type. Note that the binder resin is contained in the charge generation layer 5 and the charge transfer layer 6 in the laminated type, and in the photosensitive layer 14 in the dispersion type.

Hereinafter, the electrophotographic photosensitive member according to the present embodiment will be described separately for the case of a laminated photosensitive member and the case of a single-layer photosensitive member.

In the case of a stacked type photoreceptor, the above-mentioned crystalline oxotitanyl phthalocyanine is used as the charge generating substance 2 in the charge generating layer 5, and the above-mentioned other charge generating substance 2 may be contained. . The charge transfer layer 6 contains the diamine compound as the charge transfer material 3, and may contain various additives such as a leveling agent, an antioxidant, and a sensitizer as needed. In particular, α-tocopherol and 2,6-di-t-butyl-4-methyl-phenol are preferred as antioxidants. α-Tocopherol is preferably contained in an amount of 0.1% by weight or more and 5% by weight or less based on the charge transfer material 3, and 2,6-di-t-butyl-4-.
It is preferable that methyl-phenol is contained in an amount of 0.1% by weight or more and 50% by weight or less based on the charge transfer material 3. Thereby, the potential characteristics are excellent, and the stability as a coating solution is also enhanced.

As a method for forming each layer, a known method such as sequentially applying a coating solution obtained by dissolving or dispersing a substance to be contained in a layer in a solvent can be applied.

The charge generation layer 5 may be formed by vacuum deposition, sputtering, or CVD (Chemical Vapor D).
eposition) and a coating method. In the coating method, the charge generating substance 2 is dissolved in a solvent,
Or pulverized and dispersed by a ball mill, sand grinder, paint shaker, ultrasonic disperser, etc., add a binder resin and a solvent as needed, and in the case of a sheet, a baker applicator, bar coater, casting and spin coating, etc. In the case of a drum, the charge generation layer 5 is formed by a spray method, a vertical ring method, a dip coating method, or the like.

In particular, in the method of applying the dispersion, the coating layer can be made to have an arbitrary thickness, and the exposed laser beam can be absorbed to eliminate the reflection from the substrate, so that the reproducibility is good and the control is easy. In addition, the method of applying the dispersion liquid does not require a high vacuum device at the time of vapor deposition as compared with the vapor deposition method, and can avoid thermal decomposition and thermal denaturation due to heating, such as crystallization of the vapor deposited product after vapor deposition. This is advantageous because there is no trouble in industrial production.

Solvents include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, ethers such as tetrahydrofuran and dioxane, and aromatic hydrocarbons such as benzene, toluene and xylene. And aprotic polar solvents such as N, N-dimethylformamide and dimethylsulfoxide can be used alone or in combination of two or more.

The charge generation layer 5 has a thickness of 0.05 to
It is preferably 5 μm, more preferably 0.08 to 1 μm.

The charge transfer layer 6 can be formed by dissolving the charge transfer material 3 in a solvent and adding a binder resin, for a sheet, such as a baker applicator, a bar coater, casting and spin coating, and for a drum, The charge transfer layer 6 is formed by applying a spray method, a vertical ring method, a dip coating method, or the like.

Examples of the binder resin include vinyl polymers such as polymethyl methacrylate, polystyrene and polyvinyl chloride, and copolymers thereof, polycarbonate resins, polyester resins, polyester carbonate resins, polysulfone resins, phenoxy resins, epoxy resins, and silicone resins. Resins. These may be used singly or as a mixture of two or more kinds. In addition, a copolymer of a monomer necessary for constituting the resin, and a thermosetting resin partially crosslinked can also be used.

Solvents include ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; ethers such as tetrahydrofuran and dioxane; aromatic hydrocarbons such as benzene, toluene and xylene; N
Aprotic polar solvents such as dimethylformamide and dimethylsulfoxide can be used.

The thickness of the charge transfer layer 6 is preferably 5 to 60 μm, more preferably 10 to 40 μm.

Usually, the charge transfer layer 6 is formed on the charge generation layer 5, but the reverse is also possible. Further, as the outermost surface layer, for example, a conventionally known overcoat layer mainly composed of a thermoplastic or thermosetting polymer may be provided.

In the case of a single layer type photosensitive layer, the charge transfer layer having the same compounding ratio as that of the charge transfer layer 6 in the multilayer type photoreceptor is used.
Oxotitanyl phthalocyanine of the above-mentioned crystal type is dispersed. The particle size of the oxotitanyl phthalocyanine needs to be sufficiently small, and is preferably used at 1 μm or less. When the amount of the charge generating substance 2 dispersed in the photosensitive layer 14 is too small, the sensitivity is insufficient, and when the amount is too large, adverse effects such as lowering of chargeability and sensitivity are caused. Is used at 1 to 20% by weight. The thickness of the photosensitive layer 14 is preferably 5 to 50 μm,
It is more preferably used at 10 to 40 μm.

The photosensitive layer 14 in the single-layer type photoreceptor also has a conventionally known plasticizer for improving film formability, flexibility and mechanical strength, an additive for suppressing residual potential, dispersion stability. A dispersing aid for improving the properties, a leveling agent for improving the coating properties, a surfactant, a silicone oil, a fluorinated oil, and other additives may be added. In particular, dimethylpolysiloxane is preferable as the leveling agent, and 0.001% by weight based on the binder resin.
Preferably, it is contained in an amount of at least 5% by weight. As a result, a photoconductor having excellent surface properties can be obtained, and the potential characteristics can be improved.

Examples of the conductive support 1 used in the embodiment of the present invention include those having a substrate itself having conductivity.
For example, aluminum, aluminum alloys, copper, zinc,
Stainless steel, nickel, titanium and the like can be used. In addition, plastic and paper on which aluminum, gold, silver, copper, zinc, nickel, titanium, indium oxide, tin oxide, and the like are deposited, plastic and paper containing conductive particles, and plastic containing a conductive polymer are used. be able to. As their shapes, drums, sheets, seamless belts, and the like can be used.

As the intermediate layer 7 provided between the conductive support 1 and the photosensitive layer 4 or 14, an inorganic layer such as an aluminum anodic oxide film, aluminum oxide, aluminum hydroxide and titanium oxide, as well as polyvinyl alcohol, polyvinyl Butyral, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, polyamide, casein, and N
-Methoxymethylated nylon and the like are used. Further, particles such as titanium oxide, tin oxide and aluminum oxide may be dispersed therein.

The characteristic of the electrophotographic photoreceptor according to the embodiment of the present invention obtained as described above is that the oxotitanyl phthalocyanine used for the photoreceptor exhibits a large sensitivity even in a long wavelength range, and thus the light in the long wavelength range is obtained. In particular, it has an optimum photosensitive wavelength range for a semiconductor laser and an LED (Light Emitting Diode). The oxotitanyl phthalocyanine used for the photoreceptor is characterized by having a stable crystal form, excellent crystal stability against solvents and heat, and excellent photosensitivity and repeated use characteristics as the photoreceptor. These characteristics are not only the above-mentioned properties at the time of producing oxotitanyl phthalocyanine, but also have a great advantage in producing and using an electrophotographic photosensitive member.

[0104]

EXAMPLES Hereinafter, a method for manufacturing a photoreceptor using the above-described materials and potential characteristics will be specifically described based on examples. However, the present invention is limited to the following examples unless it exceeds the gist. Not something.

(Production Example 1) o-phthalodinitrile 40
g, titanium tetrachloride 18 g and α-chloronaphthalene 5
The mixture was heated and stirred at 200 to 250 ° C. for 3 hours in a nitrogen atmosphere, allowed to react, cooled to 100 to 130 ° C., then filtered while hot, and α-chloronaphthalene 20 heated to 100 ° C.
After washing with 0 ml, a crude product of dichlorotitanium phthalocyanine was obtained. This crude product was washed with 200 ml of α-chloronaphthalene and then with 200 ml of methanol at room temperature, and further washed with 500 ml of methanol for 1 hour under hot suspension. After filtration, the obtained crude product was dissolved in 500 ml of water.
After repeated hot suspension washing until the pH reached 6 to 7, drying was performed to obtain oxotitanyl phthalocyanine intermediate crystals.

An X-ray diffraction spectrum of the obtained oxotitanyl phthalocyanine intermediate crystal was measured under the following conditions. The oxotitanyl phthalocyanine obtained in Production Examples 1 to 3 described below was also measured under the same conditions. X-ray source CuKα = 1.54050 ° Voltage 40 kV Current 50 mA Start angle 5.0 deg. Stop angle 30.0 deg. Step angle 0.02 deg. Measurement time 0.5 deg. / Sec Measurement method θ / 2θ Scan method

FIG. 5 is a view showing an X-ray diffraction spectrum of an oxotitanyl phthalocyanine intermediate crystal obtained during the production of Production Example 1 of the present invention. This intermediate crystal has a maximum diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.3 ° and diffraction peaks at 7.4 °, 9.6 ° and 27.3 °. It can be seen that it is a crystal type oxotitanyl phthalocyanine called a Y type described in 8256 and JP-A-7-271073.

1.0 g of these crystals was dissolved in methyl ethyl ketone 3
After mixing with 0 g, the mixture was milled with glass beads having a diameter of 2 mm by a paint conditioner (manufactured by Red Level Co., Ltd.), washed with methanol, and then dried to obtain oxotitanyl phthalocyanine crystals.

FIG. 6 is a diagram showing an X-ray diffraction spectrum of oxotitanyl phthalocyanine obtained in Production Example 1 of the present invention. This crystal has a Bragg angle (2θ ± 0.2 °)
The highest diffraction peak was shown in the overlapping peak bundle of 9.4 ° and 9.6 °, and 7.3 °, 9.4 °, 9.6 °, 1
It can be seen that the oxotitanyl phthalocyanine of the specific crystalline form in the present invention has diffraction peaks at 1.6 °, 13.3 °, 17.9 °, 24.1 ° and 27.2 °.

(Production Example 2) 1.0 g of oxotitanyl phthalocyanine intermediate crystal obtained in the middle of Production Example 1 and polybutyral (Eslec BL-1: manufactured by Sekisui Chemical Co., Ltd.)
0.6 g was mixed with 40 g of methyl ethyl ketone, and milled with glass beads having a diameter of 2 mm using a bead mill to obtain crystals of oxotitanyl phthalocyanine.

FIG. 7 is a view showing an X-ray diffraction spectrum of oxotitanyl phthalocyanine obtained in Production Example 2 of the present invention. This crystal has a Bragg angle (2θ ± 0.2 °)
The highest diffraction peak was shown in the overlapping peak bundle of 9.4 ° and 9.6 °, and 7.3 °, 9.4 °, 9.6 °, 1
It has diffraction peaks at 1.6 °, 13.3 °, 17.9 °, 24.1 ° and 27.2 °, and further 14.1 ° to 1
At 4.9 °, having a plurality of diffraction peaks having the same intensity, a group of peaks having a trapezoidal shape and having difficulty in separating peaks was shown, and it was found that the oxotitanyl phthalocyanine of the specific crystal type in the present invention was used. .

(Production Example 3) 1.0 g of the oxotitanyl phthalocyanine intermediate crystal obtained in the middle of Production Example 1 and polybutyral (Eslec BL-1: manufactured by Sekisui Chemical Co., Ltd.)
0.4 g and 0.2 g of a vinyl chloride-vinyl acetate copolymer resin (S-LEC M-1: manufactured by Sekisui Chemical Co., Ltd.) were mixed with 40 g of methyl ethyl ketone, and milled together with glass beads having a diameter of 2 mm by a paint conditioner. Oxo titanyl phthalocyanine crystals were obtained.

FIG. 8 is a view showing an X-ray diffraction spectrum of oxotitanyl phthalocyanine obtained in Production Example 3 of the present invention. This crystal has a Bragg angle (2θ ± 0.2 °)
The highest diffraction peak was shown in the overlapping peak bundle of 9.4 ° and 9.6 °, and 7.3 °, 9.4 °, 9.6 °, 1
It has diffraction peaks at 1.6 °, 13.3 °, 17.9 °, 24.1 ° and 27.2 °, from 14.1 ° to 14.9.
In °, a plurality of diffraction peaks having the same intensity are shown to indicate a trapezoidal shape, which is a group of difficult-to-separate peaks, and 9.4 ° and 9.6 ° overlap at the 9.0 ° position. A peak having an intensity of about half of the peak bundle is present as a shoulder peak of the peak bundle, which indicates that the oxotitanyl phthalocyanine of the present invention is a specific crystal type.

(Production Example 4) The diamine compound shown in No. 3 was produced.

33.0 g of 5-methylbenzofuran (3.
31.0 eq.), 24.0 g (1.0 eq.) Of iodine was added, and a well-stirred solution was added to 14.0 ml of nitric acid (3.0 eq.) /
A 14.0 ml solution of water was added dropwise with vigorous stirring under ice cooling. After the dropwise addition, the mixture was refluxed for 30 minutes to complete the reaction, and 100 ml of chloroform was added to the cooled reaction mixture to extract an organic layer. The organic layer was thoroughly washed with a dilute aqueous solution of NaOH and dried over calcium chloride. After evaporating the solvent, distillation under reduced pressure was performed to obtain an intermediate, 2-iodo-5-methylbenzofuran. The yield was 60%.

Next, 22.4 g (4.1 equivalents) of the obtained 2-iodo-5-methylbenzofuran, 3.68 g (1.0 equivalents) of benzidine, and 1.06 g of 18-crown-6-ether ( 0.2 equivalent), 5.1 g of copper powder
(4.0 equivalents) and 22.1 g of anhydrous potassium carbonate
(8.0 equivalents) is mixed with 150 ml of o-dichlorobenzene and heated, stirred and refluxed vigorously for 30 hours. After completion of the reaction, the filtrate was concentrated by hot celite filtration, and the residue was purified by silica gel column chromatography (eluted with n-hexane / methylene chloride = 3/7 only with methylene chloride). 9.2 g of the diamine compound 3 was obtained. The yield was 65%. The obtained Exemplified Compound No. The ¹ H-NMR spectrum of the diamine compound ^No. 3 was 2.30 ppm (s, 12H, Me), 6.8.
７7.7 ppm (m, 24H, benzene and benzofuran).

(Example 1) A polyester film on which aluminum was deposited was used as a conductive support, and 2.1 g of titanium oxide and 3.9 g of copolymerized nylon (CM8000: manufactured by Toray Industries, Ltd.) were used as the conductive support on the support. In addition to a mixed solvent of 9 g and 61.1 g of dichloroethane, a liquid dispersed for 12 hours using a paint shaker was applied and dried to form a 1 μm-thick intermediate layer.

1 part by weight of the crystalline form of oxotitanyl phthalocyanine obtained in Production Example 1 and 1 part by weight of polybutyral (Eslec BL-1; manufactured by Sekisui Chemical Co., Ltd.) were mixed with 70 parts by weight of methyl ethyl ketone, and paint condition was applied. Diameter 2
It was prepared by performing a dispersion treatment together with a glass bead of mm. The prepared solution was applied on the intermediate layer and dried to form a film having a thickness of 0.1 μm.
A 4 μm charge generation layer was formed.

Illustrative Compound No. as a charge transfer material 1 part by weight of the diamine compound, 8 parts by weight of a polycarbonate resin (II-1) and 2 parts by weight of a polyester resin (III) as a binder resin, and α-
0.2 parts by weight of tocopherol and 0.0002 parts by weight of polydimethylsiloxane as a leveling agent were mixed to prepare a 15% by weight solution using tetrahydrofuran as a solvent. The prepared solution was applied on the previously formed charge generation layer to form a charge transfer layer having a dry film thickness of 20 μm.

As described above, a laminated electrophotographic photosensitive member sample 1 comprising a charge generation layer and a charge transfer layer was obtained.

(Example 2) Using a polyester film on which aluminum was vapor-deposited as a conductive support, the solution for a charge generation layer obtained by the dispersion treatment of Example 1 was applied directly on the support and dried to form a film. A charge generation layer having a thickness of 0.4 μm was formed.

Illustrative Compound No. as a charge transfer material 3, 10 parts by weight of the diamine compound 3, 7 parts by weight of the polycarbonate resin (II-1) as the binder resin and 3 parts by weight of the polyester resin (III), and 2,6 as the antioxidant.
0.5 part by weight of -di-t-butyl-4-methyl-phenol was mixed to prepare a 15% by weight solution using tetrahydrofuran as a solvent. The prepared solution was applied on the formed charge generation layer to form a charge transfer layer having a dry film thickness of 20 μm.

Example 3 As a resin for the charge generation layer, a vinyl chloride-vinyl acetate copolymer resin (S-LEC BM-1:
A charge generation layer was formed in the same manner as in Example 1 except that Sekisui Chemical Co., Ltd.) was used.

Illustrative Compound Nos. As charge transfer materials. 10 parts by weight of a diamine compound of No. 8, 9 parts by weight of a polycarbonate resin (II-1) and 1 part by weight of a polyester resin (III) as a binder resin, 0.2 parts by weight of α-tocopherol as an antioxidant, and polydimethyl as a leveling agent 0.0002 parts by weight of siloxane was mixed to prepare a 15% by weight solution using tetrahydrofuran as a solvent. The prepared solution was applied on the formed charge generation layer to form a charge transfer layer having a dry film thickness of 20 μm.

(Example 4) A polyester film on which aluminum was deposited was used as a conductive support, and 2.1 g of titanium oxide and 3.9 g of copolymerized nylon (CM8000: manufactured by Toray Industries, Ltd.) were placed on the support. In addition to a mixed solvent of 9.9 g and 61.1 g of dichloroethane, a solution dispersed for 12 hours using a paint shaker was applied and dried to form a 1 μm-thick intermediate layer.

The same procedure as in Example 1 was repeated, except that the crystalline oxotitanyl phthalocyanine obtained in Production Example 2 was used as the charge generating substance.
A 4 μm charge generation layer was formed.

Illustrative Compound No. as a charge transfer material. 1, 10 parts by weight of a diamine compound, 8 parts by weight of a polycarbonate resin (II-1) and 2 parts by weight of a polyester resin (III) as a binder resin, and 2,6 parts as an antioxidant.
0.5 parts by weight of -di-t-butyl-4-methyl-phenol and 0.0002 parts by weight of polydimethylsiloxane as a leveling agent were mixed to prepare a 15% by weight solution using tetrahydrofuran as a solvent. The prepared solution was applied on the formed charge generation layer to form a charge transfer layer having a dry film thickness of 25 μm.

As described above, a function-separated type photoreceptor sample 4 comprising a charge generation layer and a charge transfer layer was obtained.

(Example 5) As a charge transfer material, Compound No. A function-separated photoconductor sample 5 was obtained in the same manner as in Example 4, except that the diamine compound No. 13 was used.

(Example 6) Using a polyester film deposited with aluminum as a conductive support, 2.1 g of titanium oxide and 3.9 g of copolymerized nylon (CM8000: manufactured by Toray Industries, Ltd.) were placed on this support, and methyl alcohol 32 In addition to a mixed solvent of 9.9 g and 61.1 g of dichloroethane, a solution dispersed for 12 hours using a paint shaker was applied and dried to form a 1 μm-thick intermediate layer.

The same procedure as in Example 1 was carried out except that the crystalline oxotitanyl phthalocyanine obtained in Production Example 3 was used as the charge generating substance.
A 4 μm charge generation layer was formed.

As a charge transfer material, the exemplified compound Nos. 1, 10 parts by weight of a diamine compound, 8 parts by weight of a polycarbonate resin (II-1) and 2 parts by weight of a polyester resin (III) as a binder resin, and 2,6 parts as an antioxidant.
0.5 parts by weight of -di-t-butyl-4-methyl-phenol and 0.0002 parts by weight of polydimethylsiloxane as a leveling agent were mixed to prepare a 15% by weight solution using tetrahydrofuran as a solvent. The prepared solution is applied on the previously formed charge generating layer, and the dry film thickness is 25 μm.
m of charge transfer layers were formed.

As described above, a function-separated type photosensitive member sample 6 comprising a charge generation layer and a charge transfer layer was obtained.

Example 7 As a charge transfer material, Exemplified Compound No. of the present invention was used. A function-separated type photoconductor sample 7 was obtained in the same manner as in Example 6, except that the diamine compound of No. 24 was used.

Example 8 Using an aluminum-evaporated polyester film as a conductive support, 2.1 g of titanium oxide and 3.9 g of copolymerized nylon (CM8000: manufactured by Toray Industries, Inc.) were placed on this support, and methyl alcohol 32 In addition to a mixed solvent of 9.9 g and 61.1 g of dichloroethane, a solution dispersed for 12 hours using a paint shaker was applied and dried to form a 1 μm-thick intermediate layer.

1 part by weight of the crystalline form of oxotitanyl phthalocyanine obtained in Production Example 1 was used. 1
9 parts by weight of a diamine compound, 8 parts by weight of a polycarbonate resin (II-1) and 2 parts by weight of a polyester resin (III) as a binder resin, and 2,6-di-t-butyl-4-methyl- as an antioxidant. Phenol (0.5 part by weight) was mixed to prepare a 15% by weight solution using tetrahydrofuran as a solvent. The prepared solution was dispersed together with glass beads having a diameter of 2 mm using a paint conditioner (manufactured by Red Level). The solution obtained by this dispersion was applied onto the intermediate layer to form a photosensitive layer having a dry film thickness of 25 μm.

As described above, a single-layer photoreceptor sample 8 in which the charge generating substance was dispersed in the charge transfer layer was obtained.

Example 9 A laminated photoreceptor sample 9 was obtained in the same manner as in Example 1 except that α-tocopherol was not added to the charge transfer layer.

(Example 10) 2,6-Di-
A laminated photoreceptor sample 10 was prepared in the same manner as in Example 2 except that t-butyl-4-methyl-phenol was not added.
I got

Example 11 A laminated photoreceptor sample 11 was prepared in the same manner as in Example 1 except that polydimethylsiloxane was not added to the charge transfer layer. No coating film was obtained.

Example 12 A laminated photoreceptor sample 12 was obtained in the same manner as in Example 1, except that a polycarbonate resin containing bisphenol A as a monomer component was used as the binder resin for the charge transfer layer.

Example 13 A laminated mold was prepared in the same manner as in Example 1 except that 4 parts by weight of the polycarbonate resin (II-1) and 6 parts by weight of the polyester resin (III) were used as the binder resin for the charge transfer layer. Photoconductor sample 13 was obtained.

(Example 14) As an antioxidant, 2,6
A single-layer photoreceptor sample 14 was obtained in the same manner as in Example 8, except that -di-t-butyl-4-methyl-phenol was not added.

Comparative Example 1 The procedure of Example 1 was repeated, except that an intermediate crystal of oxotitanyl phthalocyanine having the X-ray diffraction pattern shown in FIG. Function-separated photoreceptor sample 1
5 was obtained.

Comparative Example 2 The procedure of Example 2 was repeated, except that an intermediate crystal of oxotitanyl phthalocyanine having the X-ray diffraction pattern shown in FIG. Function-separated photoreceptor sample 1
6 was obtained.

(Comparative Example 3) Lamination was performed in the same manner as in Example 1 except that a 4- (diethylamino) -benzaldehyde-N, N-diphenylhydrazone compound, which was a conventionally known charge transfer material, was used as the charge transfer material. A photoreceptor sample 17 was obtained.

(Comparative Example 4) As a charge transfer material, N, N'-bis- (3-methylphenyl) -N, N'-bis- (phenyl) -benzidine (TPD) which is a conventionally known charge transfer material is used. A laminated photoreceptor sample 18 was obtained in the same manner as in Example 1 except for using.

Comparative Example 5 The same procedure as in Example 8 was carried out except that the intermediate crystal of oxotitanyl phthalocyanine having the X-ray diffraction pattern shown in FIG. 5 and obtained in the middle of Production Example 1 was used as the charge generating substance. Thus, a single-layer type electrophotographic photosensitive member sample 19 was obtained.

Comparative Example 6 The procedure of Example 8 was repeated except that a 4- (diethylamino) -benzaldehyde-N, N-diphenylhydrazone compound, which was a conventionally known charge transfer substance, was used as the charge transfer substance. A layer type photoreceptor sample 20 was obtained.

Comparative Example 7 Production Example 1 as a charge generating substance
The intermediate crystal of oxotitanyl phthalocyanine having the X-ray diffraction pattern of FIG.
A laminated photoreceptor sample 21 was obtained in the same manner as in Example 2 except that a (diethylamino) -benzaldehyde-N, N-diphenylhydrazone compound was used and α-tocopherol was not added to the charge generation layer.

Comparative Example 8 Production Example 1 as a charge generating substance
The intermediate crystal of oxotitanyl phthalocyanine having the X-ray diffraction pattern of FIG.
A laminated photoreceptor sample 22 was obtained in the same manner as in Example 11, except that the (diethylamino) -benzaldehyde-N, N-diphenylhydrazone compound was used. Could not be obtained.

Comparative Example 9 Production Example 1 as a charge generating substance
The intermediate crystal of oxotitanyl phthalocyanine having the X-ray diffraction pattern of FIG.
Using a (diethylamino) -benzaldehyde-N, N-diphenylhydrazone compound, 6 parts by weight of a polycarbonate (II-1) and 4 parts by weight of a polyester resin (III) were added as a binder resin, and no antioxidant and leveling agent were added. Except for this, a laminated photoreceptor sample 23 was obtained in the same manner as in Example 1.

Examples 1 to 14 and Comparative Examples 1 to 9
Table 5 shows the configurations of Samples 1 to 23 prepared in the above.

[0154]

[Table 5]

(Evaluation) The electrophotographic photosensitive member produced as described above was used in an electrostatic recording paper test apparatus (EPA-8200:
The electrophotographic characteristics were evaluated by Kawaguchi Electric Co., Ltd.). Regarding the laminated electrophotographic photoreceptor, applied voltage: -6 kV and static: No. 780 nm monochromatic light (irradiation light: 2 μW / c) spectrally separated by an interference filter under the measurement conditions of 3.
m ² ), the exposure E _1/2 (μJ / cm ² ) and the initial potential V ₀ (−volt) required to attenuate the voltage from −500 V to −250 V were measured. For the single-layer type electrophotographic photoreceptor, the applied voltage: +6 kV and the static: N
o. 780n, which was separated by an interference filter under the measurement conditions of 3
+50 by m monochromatic light (irradiation light: 10 μW / cm ² )
Exposure amount E required to attenuate from 0 V to +250 V
_1/2 (μJ / cm ² ) and initial potential V ₀ (+ volt) were measured.

A commercially available digital copying machine (AR513)
0: manufactured by Sharp Corp.), using the photoreceptor shown in Table 5 for the drum part, performing 30,000 continuous aerial real shots (Non Copy Aging) in which only exposure is performed without consuming toner. The charge potential and E _1/2 were measured using the electrostatic recording paper test apparatus. In a high temperature and high humidity environment (35 ° C,
85%) was performed 30,000 times, and before and after that, the residual potential was measured. In addition, a wear tester (manufactured by Suga Test Machine Co., Ltd.)
Was evaluated using The measurement conditions were as follows: abrasive: aluminum oxide # 2000, load: 200 g · f, and number of times of friction: 10,000 times.

Table 6 shows the results of the evaluation. Table 7 shows the results of visually observing the uniformity of the film on the surface of the photoreceptor.
Shown in

[0158]

[Table 6]

[0159]

[Table 7]

As shown in Table 6, in each of Examples 1 to 8, the potential deterioration after the endurance test (30,000 times) of the charging potential of each sample was smaller than that of Comparative Examples 1 to 4 which were the conventional samples. It can be seen that the characteristics are sufficiently small, the initial sensitivity (half-exposure amount) is sufficiently high as compared with the comparative example, and the sensitivity deterioration is small even after the durability test. Also, it can be seen that the residual potential rise after the durability test (30,000 times) under high temperature and high humidity in Examples 1 to 8 is sufficiently small as compared with the conventional sample.

Further, as shown in Table 7, Example 11 in which polydimethylsiloxane was not added as a leveling agent,
In Comparative Examples 7 and 8, it can be seen that a citrus skin-like defect occurs on the entire surface.

[0162]

As described above, according to the present invention, by using a specific crystalline oxotitanyl phthalocyanine as a charge-generating substance and using a benzofuran, benzothiophene or diamine compound having an indole ring as a charge-transfer substance, the longevity can be improved. An electrophotographic photoreceptor having extremely high sensitivity in a wavelength region and high durability can be provided. Therefore, the electrophotographic photoreceptor according to the present invention is suitable as a photoreceptor such as a laser printer and a digital copier using a semiconductor laser beam as a light source, which has been significantly developed recently.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating an example of an electrophotographic photosensitive member having a stacked photosensitive layer.

FIG. 2 is a cross-sectional view schematically illustrating an example of an electrophotographic photosensitive member having a dispersion type photosensitive layer.

FIG. 3 is a cross-sectional view showing an example having an intermediate layer 7 in the electrophotographic photoreceptor of FIG.

FIG. 4 is a cross-sectional view showing an example having an intermediate layer 7 in the electrophotographic photoreceptor of FIG.

FIG. 5 is a view showing an X-ray spectrum of an oxotitanyl phthalocyanine intermediate crystal obtained in the course of production in Production Example 1 of the present invention.

FIG. 6 is a view showing an X-ray spectrum of oxotitanyl phthalocyanine obtained in Production Example 1 of the present invention.

FIG. 7 is a view showing an X-ray spectrum of oxotitanyl phthalocyanine obtained in Production Example 2 of the present invention.

FIG. 8 is a view showing an X-ray spectrum of oxotitanyl phthalocyanine obtained in Production Example 3 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive support 2 Charge generation material 3 Charge transfer material 4, 14 Photosensitive layer 5 Charge generation layer 6 Charge transfer layer 7 Intermediate layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 5/147 504 G03G 5/147 504 F-term (Reference) 2H068 AA04 AA13 AA16 AA19 AA20 AA31 AA37 BA12 BA14 BA16 BA39 BA60 BB23 BB26 BB32 BB54

Claims (12)

[Claims] 1. A photosensitive layer formed on a conductive substrate is used as a charge generating substance in an X-ray diffraction spectrum at Bragg angles (2θ ± 0.2 °) of 7.3 °, 9.4 °, and 9. 6
°, 11.6 °, 13.3 °, 17.9 °, 24.1 °
And 27.2 ° show major diffraction peaks, of which the overlapping peak bundle of 9.4 ° and 9.6 ° shows the largest diffraction peak, and the peak at 27.2 ° shows the second largest peak. An electrophotographic photoreceptor, comprising: a crystalline oxotitanyl phthalocyanine as described above; and a charge transfer material comprising a benzofuran, benzothiophene, or diamine compound having an indole ring represented by the following general formula (I). Embedded image (Wherein, Ar ¹ is an arylene group which may contain a substituent,
It represents a divalent heterocyclic group which may contain a substituent or an alkylene group having 1 to 5 carbon atoms which may contain a substituent. Ar ²
Is an aryl group which may have a substituent, a heterocyclic group which may have a substituent, an aralkyl group which may have a substituent,
Examples thereof include an alkyl group having 1 to 5 carbon atoms which may have a substituent, a fluoroalkyl group having 1 to 5 carbon atoms which may have a substituent and a perfluoroalkyl group having 1 to 5 carbon atoms which may have a substituent. R ¹ is an alkyl group having 1 to 3 carbon atoms which may have a substituent, and ¹ carbon atom which may have a substituent.
A fluoroalkyl group having 1 to 5 carbon atoms, a perfluoroalkyl group having 1 to 5 carbon atoms which may contain a substituent, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, or a hydrogen atom. a represents 1 carbon atom which may contain a substituent;
Alkyl groups having 1 to 3 carbon atoms which may contain a substituent.
A fluoroalkyl group having 1 carbon atom which may contain a substituent
A perfluoroalkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and n represents an integer of 1 to 4. However, when n is 2 or more, each of a may be the same or different, and may form a ring with each other. X represents an oxygen atom, a sulfur atom or N—R ² , and R ² represents an alkyl group having 1 to 3 carbon atoms which may have a substituent, a fluoroalkyl group having 1 to 5 carbon atoms which may have a substituent or a substituent. A perfluoroalkyl group having 1 to 5 carbon atoms which may contain a group is shown. ) 2. The electron according to claim 1, wherein the photosensitive layer has a laminated structure including a charge generation layer containing the charge generation material and a charge transfer layer containing the charge transfer material. Photoreceptor. 3. The electrophotographic photoreceptor according to claim 1, wherein said photosensitive layer comprises a single layer containing said charge generating substance and said charge transfer substance. 4. The electrophotographic photosensitive member according to claim 1, wherein an intermediate layer is provided between the conductive support and the photosensitive layer. 5. The charge transfer layer, as a binder resin, a polymer of a vinyl compound and a copolymer thereof, a polyester resin, a polycarbonate resin, a polyarylate resin, a polysulfone resin, a polyvinyl butyral resin, a phenoxy resin, a cellulose resin, At least one selected from the group consisting of urethane resins and epoxy resins
3. The electrophotographic photoreceptor according to claim 2, comprising a seed. 6. The photosensitive layer, as a binder resin, is a polymer of a vinyl compound and a copolymer thereof, a polyester resin, a polycarbonate resin, a polyarylate resin, a polysulfone resin, a polyvinyl butyral resin, a phenoxy resin, a cellulose resin, a urethane resin. The electrophotographic photoreceptor according to claim 3, comprising at least one selected from the group consisting of a resin and an epoxy resin. 7. The binder resin according to the following general formula (I)
The electrophotographic photoreceptor according to claim 5, further comprising a polycarbonate resin represented by I). Embedded image (In the formula, b and c each have an alkyl group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, Carbon number 7
To 17 aralkyl groups, alkenyl groups having 2 to 5 carbon atoms,
Represents an alkoxy group having 1 to 5 carbon atoms, a halogen atom or a hydrogen atom. X ² may be a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, a cyclic alkylidene group having 1 to 10 carbon atoms which may have a substituent, or a substituent. A good arylene group having 6 to 12 carbon atoms, a sulfonyl group or a carbonyl group is represented, m and l are integers of 1 to 4, and u is an integer of 10 to 200. Z is an alkylene group having 1 to 5 carbon atoms which may have a substituent;
12 represents an arylene group or an arylene alkyl group having 7 to 17 carbon atoms. W is a carbon atom which may have a substituent;
To 5 alkyl groups, 2 to 5 carbon atoms which may have a substituent
An alkenyl group, an alkoxy group having 1 to 5 carbon atoms, an alkyl ester group having 1 to 5 carbon atoms which may have a substituent, an aryl ester group having 6 to 12 carbon atoms which may have a substituent, Represents a group, an aldehyde group, a hydroxyl group, a halogen atom, or a hydrogen atom. ) 8. The method according to claim 1, wherein the binder resin has the following general formula (II)
The electrophotographic photoreceptor according to claim 7, wherein the polyester resin represented by I) is contained in an amount of 5% by weight or more and 50% by weight or less of the total amount of the binder resin. Embedded image (Where g, h and i represent an integer of 1 to 10,
v, w, x, and y represent an integer of 10 to 1000. ) 9. The electrophotographic photosensitive member according to claim 8, wherein the weight ratio of the polycarbonate resin / the polyester resin is in a range of 9/1 to 7/3. 10. The photosensitive layer contains α-tocopherol as an antioxidant, and the weight ratio of antioxidant / charge transfer material is 0.1 / 100 or more and 5/100 or less. 8. The electrophotographic photosensitive member according to any one of 1 to 7. 11. The photosensitive layer according to claim 2, wherein said antioxidant is 2,6.
-Di-t-butyl-4-methyl-phenol,
Antioxidant / charge transfer material weight ratio of 0.1 / 100
The ratio is not less than 50/100 and not more than 50/100.
8. The electrophotographic photosensitive member according to any one of items 1 to 7, 12. The method according to claim 1, wherein the surface layer contains dimethylpolysiloxane at a weight ratio of dimethylpolysiloxane / binder resin of 0.001 / 100 or more and 5/100 or less. The electrophotographic photoreceptor according to any one of the above.